This invention relates to electrolytic reactors used for water treatment and more particularly to a rectangular electrolytic reactor for supporting multiple plate electrodes that is constructed from plastic materials and capable of operating under pressure.
As it is well understood, electrolytic reactors have been used for many types of water treatment processes as an alternative to using treatment chemicals. Electrocoagulation is a popular and more recently used term to describe one of several processes where the present invention can be applied. The process of electrocoagulation involves passing contaminated water between electrodes connected to a source of DC power. The high voltage potential applied to the electrodes forces metal ions to liberate from the surface of electrodes and into the water, causing impurities to coagulate into a larger and denser solid that can then be removed by settling or using conventional filtration equipment. Another example of a process where the present invention could be applied is described in U.S. Pat. No. 4,693,798 and includes a reactor containing two or more electrodes that is used for producing a metal ion solution that can be added to contaminated water for treatment. The process works by adding acid to clean makeup water and then continuously circulating the low pH water through the reactor. The applied DC power forces metal ions to release from the electrodes and mix into the water, thus generating a concentrated solution of metal ions that can be added directly to contaminated water to facilitate precipitation of suspended solids and other contaminants.
Many treatment applications use electrolytic reactors that are sealed and capable of operating under pressure. It is also preferred to use a reactor that supports plate electrodes for ease of maintenance, while also being constructed from plastic material to prevent corrosion and permit the reactor to be flushed periodically with high strength acid to clean the surface of electrodes. In addition, many electrolytic reactors include complex electrical connectors arrangements that make it difficult seal the reactor, therefore, it is also preferred to provide better means of connecting power to electrodes that would prevent the reactor housing from leaking.
U.S. Pat. No. 4,036,726 discloses a tubular reactor housing for supporting multiple plate electrode spaced evenly apart to permit water to flow vertically from the bottom of the reactor and in between the electrically charged electrodes where water is subjected to treatment, followed by exiting the side of the housing near the top of the reactor. The problem with this design is it contains several void and unusable areas in between the plates and the inner wall of the tubular housing, requiring additional unnecessary space that would preferably be used to hold additional electrodes. In addition to the void areas within the reactor housing, the external shape of a cylindrical reactor provides an inefficient use of external space and requires much more area to operate than a rectangular reactor containing the identical size and number of plate electrodes. This type of tubular reactor offers few design options as tubing and piping is typically offered in nominal sizes with very few material options. In addition, the reactor, including the tubular housing, supporting base, and internal components are welded together, preventing disassembly to replace or repair damaged components. A further problem is the method by which electrical connections are made to the electrode plates consist of traditional bolts and nuts that provide an insufficient method of sealing and would require sealing compound each time electrode plates are exchanged for maintenance.